THE FUNGI WHICH CAUSE PLANT DISEASE 123 



E. mali Lewis ^ 



Mycelium well developed, multiseptate; conidia formed on 

 short conidiophores or on the ends of short germ tubes, averag- 

 ing 3 X 8 m; no yeast-like budding; asci usually 

 on short lateral branches, 11-14 /i in diameter; 

 ascospores sphseroidal, slightly elongate, 4.5 x 

 5.5 ju with thickened places on the walls, brown 

 when mature. Figs. 83, 84. ^^^' g^ _E. ^.^i;. 



Lewis isolated the fungus from decayed spots Typical manner 

 on apples by plate cultures. Inoculations proved on agar. After 

 that it is capable of causing a slow decay with- ^'^^ 

 out the aid of other fungi. An extensive cultural study as well as 

 a considerable cytological study was made. 



£. decipiens (Tul.) Rees is parasitic on Armillaria; E. parasitica 

 Fayed on Tricholoma."' " 



Euascomycetes (p. 117) 



This is an extraordinarily large group comprising some 16,000 

 species, with great variety of size, color and shape of plant body. 

 Most of them are saprophytes, still many are parasites either in 

 their ascigerous or their conidial stages of development. 



The twelve orders may be recognized by the following key. 



Key to Orders of Euascomycetes 



Asci approximate in an indefinite hyme- 



nium, no ascoma 1- Protodiscales, p. 125. 



Asci grouped in a definite ascoma 

 Asci collected in a flattened, concave or 

 closed ascoma, often bordered by a 

 distinct layer 

 Ascoma at maturity open and more or 

 less cup-like. Discomycetes 

 Ascoma open from the first, clavate or 



convex, pitted, or gyrose 2. Helvellales, p. 130. 



Aspoma at first closed, opening early, 

 without special covering, more 

 or less fleshy 3. Pezizales, p. 133. 



